engineer wrote:
I think that bluetooth can support a basic rate much faster than you quote.
From my reading of the specs (Core Specification, Volume 1), using differential BFSK modulation, Bluetooth has a raw rate of 1 mega symbols per second. The FSK pair is then hopped at the packet rate.
Hopping with a single frequency slot will thus give a basic Bluetooth device a raw thruput of 1 Mbits/sec. Somewhere else, I have seen Bluetooth quoted as 750 kilobits/sec after the packet overhead.
Now, it is possible, at extra expense and more bandwidth occupancy, for a Bluetooth device to hog more than one frequency slot. For example, if the device uses 2 of the slots at any given time, you can then achieve 1.5 Mbits/sec effective transfer rates. One can think of this as having a constellation of 2 symbols,
On the other side of the picture [pun intended], my Nikon 950 camera, using JPEG compression, compresses a typical image to about 750 kilo-bytes. This is not the highest quality mode for the camera, either. Further, this is a generation-old camera. The current generation cameras have higher resolutions than my relic and the number of pixels is proportional to the square of resolution!
Regards,
Kok Chen |
